org.apache.commons.collections4.map
Class CaseInsensitiveMap<K,V>
java.lang.Object
java.util.AbstractMap<K,V>
org.apache.commons.collections4.map.AbstractHashedMap<K,V>
org.apache.commons.collections4.map.CaseInsensitiveMap<K,V>
- All Implemented Interfaces:
- Serializable, Cloneable, Map<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>
public class CaseInsensitiveMap<K,V>
- extends AbstractHashedMap<K,V>
- implements Serializable, Cloneable
A case-insensitive Map
.
Before keys are added to the map or compared to other existing keys, they are converted
to all lowercase in a locale-independent fashion by using information from the Unicode
data file.
Null keys are supported.
The keySet()
method returns all lowercase keys, or nulls.
Example:
Map<String, String> map = new CaseInsensitiveMap<String, String>();
map.put("One", "One");
map.put("Two", "Two");
map.put(null, "Three");
map.put("one", "Four");
creates a CaseInsensitiveMap
with three entries.
map.get(null)
returns "Three"
and map.get("ONE")
returns "Four".
The Set
returned by keySet()
equals {"one", "two", null}.
This map will violate the detail of various Map and map view contracts.
As a general rule, don't compare this map to other maps. In particular, you can't
use decorators like ListOrderedMap
on it, which silently assume that these
contracts are fulfilled.
Note that CaseInsensitiveMap is not synchronized and is not thread-safe.
If you wish to use this map from multiple threads concurrently, you must use
appropriate synchronization. The simplest approach is to wrap this map
using Collections.synchronizedMap(Map)
. This class may throw
exceptions when accessed by concurrent threads without synchronization.
- Since:
- 3.0
- Version:
- $Id: CaseInsensitiveMap.java 1477799 2013-04-30 19:56:11Z tn $
- See Also:
- Serialized Form
Nested classes/interfaces inherited from class org.apache.commons.collections4.map.AbstractHashedMap |
AbstractHashedMap.EntrySet<K,V>, AbstractHashedMap.EntrySetIterator<K,V>, AbstractHashedMap.HashEntry<K,V>, AbstractHashedMap.HashIterator<K,V>, AbstractHashedMap.HashMapIterator<K,V>, AbstractHashedMap.KeySet<K>, AbstractHashedMap.KeySetIterator<K>, AbstractHashedMap.Values<V>, AbstractHashedMap.ValuesIterator<V> |
Nested classes/interfaces inherited from interface java.util.Map |
Map.Entry<K,V> |
Fields inherited from class org.apache.commons.collections4.map.AbstractHashedMap |
DEFAULT_CAPACITY, DEFAULT_LOAD_FACTOR, DEFAULT_THRESHOLD, GETKEY_INVALID, GETVALUE_INVALID, MAXIMUM_CAPACITY, NO_NEXT_ENTRY, NO_PREVIOUS_ENTRY, NULL, REMOVE_INVALID, SETVALUE_INVALID |
Constructor Summary |
CaseInsensitiveMap()
Constructs a new empty map with default size and load factor. |
CaseInsensitiveMap(int initialCapacity)
Constructs a new, empty map with the specified initial capacity. |
CaseInsensitiveMap(int initialCapacity,
float loadFactor)
Constructs a new, empty map with the specified initial capacity and
load factor. |
CaseInsensitiveMap(Map<K,V> map)
Constructor copying elements from another map. |
Methods inherited from class org.apache.commons.collections4.map.AbstractHashedMap |
addEntry, addMapping, calculateNewCapacity, calculateThreshold, checkCapacity, clear, containsKey, containsValue, createEntry, createEntrySetIterator, createKeySetIterator, createValuesIterator, destroyEntry, doReadObject, doWriteObject, ensureCapacity, entryHashCode, entryKey, entryNext, entrySet, entryValue, equals, get, getEntry, hash, hashCode, hashIndex, init, isEmpty, isEqualKey, isEqualValue, keySet, mapIterator, put, putAll, remove, removeEntry, removeMapping, reuseEntry, size, toString, updateEntry, values |
CaseInsensitiveMap
public CaseInsensitiveMap()
- Constructs a new empty map with default size and load factor.
CaseInsensitiveMap
public CaseInsensitiveMap(int initialCapacity)
- Constructs a new, empty map with the specified initial capacity.
- Parameters:
initialCapacity
- the initial capacity
- Throws:
IllegalArgumentException
- if the initial capacity is negative
CaseInsensitiveMap
public CaseInsensitiveMap(int initialCapacity,
float loadFactor)
- Constructs a new, empty map with the specified initial capacity and
load factor.
- Parameters:
initialCapacity
- the initial capacityloadFactor
- the load factor
- Throws:
IllegalArgumentException
- if the initial capacity is negative
IllegalArgumentException
- if the load factor is less than zero
CaseInsensitiveMap
public CaseInsensitiveMap(Map<K,V> map)
- Constructor copying elements from another map.
Keys will be converted to lower case strings, which may cause
some entries to be removed (if string representation of keys differ
only by character case).
- Parameters:
map
- the map to copy
- Throws:
NullPointerException
- if the map is null
convertKey
protected Object convertKey(Object key)
- Overrides convertKey() from
AbstractHashedMap
to convert keys to
lower case.
Returns AbstractHashedMap.NULL
if key is null.
- Overrides:
convertKey
in class AbstractHashedMap<K,V>
- Parameters:
key
- the key convert
- Returns:
- the converted key
clone
public CaseInsensitiveMap<K,V> clone()
- Clones the map without cloning the keys or values.
- Overrides:
clone
in class AbstractHashedMap<K,V>
- Returns:
- a shallow clone
Copyright © 2001–2013 The Apache Software Foundation. All rights reserved.